For many years, a standard container in the beer and beverage industry has been a can of so-called three-piece construction which consists of a cylindrical body that is formed by rolling a flat blank into a cylinder, interlocking the edges of the blank and soldering the edges to produce a cylindrical body. Two end panels are then attached to opposite ends of the cylindrical body by a double seaming process.
The quite recent alternate to the three-piece container is what is commonly referred to as a two-piece container. In forming a two-piece container, a metal blank is impact extruded or deep drawn to produce a cylindrical body and an integral bottom end wall. In this type of container, the second piece of the two-piece container consists of an end panel that is separately formed and attached to the upper end of a cylindrical body by a double seaming process. A container manufactured according to this process has a larger outside diameter along the upper edge where the double seaming operation has been performed than the diameter of the remainder of the container. Thus, when cans such as these are placed in a multi-pack carrier, such as a so-called six-pack carton which grips the upper double seam, the package, when viewed from the end, is slightly trapezoidal in shape. This, of course, results from the larger outside diameter of the double seam at the top of the containers.
To overcome this problem, some beer and beverage containers are being manufactured with a reduced diameter neck portion that is produced on the upper free edge of the integral body and bottom wall so that when a double seam is formed, the outer edges of the seam are approximately parallel or flush with the outer peripheral surface of the remainder of the can body. This provides a more compact packing of cans which in turn lowers the total shipping and storage costs. Because of the reduced cost and the pleasing esthetics of these types of containers, the demand for containers of this type is substantial and is continually increasing.
Because of the increase demand, considerable efforts have been devoted to producing apparatus which is capable of producing the reducing neck and the peripheral flange on a container body. Heretofore, it has been customary for the necking and the flanging operation to be performed by completely separate machines. One type of apparatus for producing the reducing neck consists of an annular die that is used to engage the peripheral surface of the free edge portion of the container body while the container is supported at the bottom. When using this type of necking apparatus, it is necessary that a lubricant be applied to the peripheral edge portion of the container before the reducing neck is formed by the annular die.
In the past, it has been customary for the lubricant to be applied by a separate apparatus and the can then fed from the lubricant applying machine to a necking machine through a chute. The containers are normally in a position where the axis of the cylindrical body is generally horizontal so that the container can be fed into the necking apparatus by gravity through a chute extending from the lubricant applying means or waxer to the necking apparatus. After the containers have the reducing neck produced thereon, they are again gravity fed through chutes from the necking apparatus to a separate flanging apparatus where the outwardly directed flange is produced thereon.
One of the problems encountered with an operation of this type is the amount of floor space that must of necessity be utilized for the separate machines. Furthermore, in order to rely upon gravity transfer of the containers between the machines, the lubricant applying machine must be supported at a substantial elevation above the floor of a building housing the apparatus while the necking apparatus must also be supported by frame structure above the floor.
An additional problem encountered with heretofore known method and apparatus for producing a neck and a flange on a container body is the fact, when relying upon gravity feeding, the containers are continuously subjected to possible damage, such as denting, while they are being transferred from one location to another. This problem is particularly acute when the containers are formed of thin gage aluminum.
A further problem with the previously known method of waxing, necking and flanging the open end of a drawn and ironed container is that the speed of operation is to some extent limited.